I'm having issues. I've tried numerous times and I can't get my fine lines to burn clearly on the screen. I have a ryonet exposure unit, using dual core diazo emulsion, and burning for 5 minutes. What's the problem? I've tried burning it longer, it does not work, i've tried burning it shorter, it does not work. I even wash it down with a pressure washer and light scrubbing and it still does not work . What's happening? What am I doing wrong? Please help.
More about screen printing mesh size: Different mesh sizes are used for different applications in the screen printing process. Mesh size is measured by how many threads of mesh there are crossing per square inch. For instance, a 110 mesh screen has 110 threads crossing per square inch. The higher the mesh count, the finer the threads and holes are in the screen. The size of the mesh has a lot to do with how detailed your image is and how thick the ink you are using is. If you have an image with extremely high detail, a lower mesh screen won’t hold the high detail. The fine lines or dots in the image will simply fall through the holes in the mesh not giving you a correct representation of what your image should be.
the mesh size I'm using is 156. Using genesis plastisol ink
Well, I don't burn screens but I'm an artist & separator and when sending film separations with fine details to the screen department, the returning screens with fine details would be on 305 (or was it 301.. .not sure) mesh.
Is the positive very dark and dense? Also do you have a vacuum on your exposure unit? If not, you need to make sure the film is in intimate contact with the screen during exposure. You dont want light to "undercut" the film and cause the fine lines to close up during burning.
I don't know how dark it should be but it's laser printed. It's dark enough if you ask me. No vacuum on my exposure unit, but there is film to screen direct contact. I dont' know what else to do. So much emulsion has been wasted because of this.
Just because you have your positive between the glass and screen does not mean there is direct contact all the way through. How much weight are you putting on it? (I assume you are putting down a foam block into the frame, then a bunch of heavy crap on top. It sounds like you should have done a step-wedge test to determine the best exposure time. Also try some Toner-Aid it will darken your positive.
I have the same equiptment and have had that problem. Sometimes, the transparencies aren't tight up against the screen....I try to use more tape and make sure its STUCK on the screen....this way you get a tight burn on the screen....hope this helps.
White mesh and amber mesh are very different.
Light travels along the threads of white mesh and has somewhat of a prism effect on your exposure, casting light in different directions around the thread and distorting the exposure. White mesh is fine for solid images or large half tones.
I would also say 156 is too low of a mesh for fine detail and I think but I'm not sure most screen companies only supply amber above a 180. You can request 156 amber mesh but I think that is as low as you can get with amber.
Try some high mesh you'll like it
NB why aren't my fine lines burning 
Re: NB why aren't my fine lines burning 
